This study will establish criteria for the evaluation of the nerve fiber layer (NFL) of the retina. It will document the appearance of the nerve fiber layer in normal and in specific pathological conditions. Fundus photography will be utilized to record objectively the appearance of the nerve fiber layer. In addition, this study will identify optimal photographic methods for the evaluation of nerve fiber detail. We will use fundus photography with Wratten and interference filters and new films with increased definition and greater sensitivity in the "red-free" range of the spectrum. Standard color photography and stereo photography will be used as baselines. Photographs will be taken of the fundus in both light and dark adapted states. The variations in the fundus appearance both on ophthalmoscopic and photographic examination will be recorded. Correlative studies by means of visual acuity and visual field examination, color vision testing, macular photo-stress, ophthalmodynamometry and fluorescein angiography will be included in the evaluation. The results of this study will be directly applicable to screening for diseases which affect the nerve fiber layer of the retina, to early recognition of specific disease processes and to their differential diagnosis, and to the evaluation of both prognosis and treatment efficacy.